The invention pertains to a nozzle for use in aircraft fueling. More particularly, it pertains to the construction of a fueling nozzle which is rugged, compact, lightweight and easy to repair.
A typical aircraft fueling nozzle has a poppet type fluid control valve. The valve is adapted at an outlet end for connection to a fueling flange on an aircraft, and at an inlet end for connection to a fuel supply hose. The poppet has a head and a stem which rides in and is guided by a bearing sleeve that is attached to the valve body via one or more webs. The valve is actuated via a linkage comprising an arm rotatably connected to the valve stem, a crank rotatably connected to the arm and means for actuating the crank, such as a hand operated lever connected to the crank via a shaft.
In one common design, a single crank is used with two arms, one at either side of the crank and valve stem. The arms are connected to the crank via an axle pin and connected to the stem via a second axle pin extending through the stem. With the crank disposed adjacent the inlet end of the nozzle body, the arms extend downstream, toward the outlet end, where they are connected to an end of the valve stem upstream of the bearing sleeve. The valve stem extends through the bearing sleeve with the poppet head mounted at an end of the valve stem downstream of the bearing sleeve. The resulting nozzle is of such length as is necessary to accommodate the linkage, an area of the valve stem upstream of the bearing sleeve, the bearing sleeve itself and the poppet head. Enough length of stem must exist upstream of the bearing sleeve to give the valve a sufficient range of motion without the arm interfering with the bearing sleeve. Nozzles according to such construction have been criticized for high weight and difficulty in handling, resulting from the length of the nozzle.
To address such concerns, U.S. Pat. No. 4,567,924 to Albert W. Brown, discloses a nozzle which has a slot formed in the bearing sleeve and extending from the upstream end thereof. A corresponding slot is formed in the valve stem. The nozzle uses a single arm which extends into the slot in the valve stem, and is rotatably connected thereto by a pin which extends through the stem. When the linkage moves the valve, the arm can pass through the slot in the bearing sleeve. Accordingly, the necessary length of the nozzle is reduced.
In the Brown fueling nozzle, the crank is attached to the shaft via four bolts. To access the bolts for removing the crank, one must carefully insert a driver through the nozzle accessory port and one by one remove the bolts. Furthermore, to subsequently remove the stem and linkage, the poppet head must be removed from the stem, such as by removal of a cotter pin which extends through the head and the downstream end of the stem. Subsequently the stem and linkage may be extracted through the inlet port.
In the two-armed design, such as is used in a prior nozzle manufactured by the assignee of the applicant, the actuator shaft extends all the way through the housing. The crank is secured to the shaft via hexagonal interlocking features formed respectively on the shaft and on a shaft receiving bore through the crank. The arms are secured to the crank and also secured to the upstream end of the stem via axle pins having a head at one end of each pin and a cotter pin at the other end of each pin. The actuating lever is located at one end of the shaft and a cotter pin is inserted through the other end of the shaft. To remove the shaft, the cotter pin is removed and the shaft is extracted from the body and crank. Subsequently, as with the Brown nozzle, the linkage may be removed after separating the poppet head from the stem, with the head cotter pin being accessible when the poppet is in an open orientation.
In the prior product manufactured by the assignee of the applicant, the valve seat is supported and biased toward the head via an annular wave spring. To retain the seat in the nozzle when the poppet is in the open position, a retainer clip is provided to secure the nozzle to the body. The retainer clip has two outwardly projecting annular lips. The seat has an inwardly projecting annular lip as does the nozzle body. The clip is placed over the inwardly projecting annular lips so that the lips of the seat and the body are held between the lips of the clip with the lip of seat being downstream of the lip of the body. With the valve closed, the wave spring is compressed and the retainer clip does not engage the lips of the seat and body. However, as the valve is opened the seat gradually moves downstream with the valve until the seat lip engages the downstream retainer clip lip and the body lip engages the upstream retainer clip lip to restrict further movement. In order to replace the seat, the poppet head must be removed from the stem permitting access to the retainer clip which is removed using a special tool. With the clip removed the seat may be extracted by hand.
In the prior product manufactured by the assignee of the applicant, the nozzle has a connector for mating with a fueling flange of an aircraft. The fueling flange has an annular rim with three radially outwardly projecting lugs and three slots intermediate the lugs. The connector has three ramps interspaced with three slots which are configured to receive the fueling flange lugs. When the nozzle is mated with the fueling flange, the lugs pass through the slots as the flange depresses a spring-loaded lock plate. The flange is secured to the nozzle against rotation by pins which are attached to the nozzle body and extend into the slots on the fueling flange. When the lock plate is depressed, the connector may be rotated so that the lugs are secured beneath the ramps thereby firmly connecting the flange to the nozzle.